Modulelens-5.3.5Haskell2010

Data.HashSet.Lens

3 values

Packagelens-5.3.5
Exports3
LanguageHaskell2010
LicenceBSD-2-Clause
SourceLens.hs

valuesetmapped :: (Eq j, Hashable j) => IndexPreservingSetter (HashSet i) (HashSet j) i j

This Setter can be used to change the type of a HashSet by mapping the elements to new values.

Sadly, you can't create a valid Traversal for a Set, but you can manipulate it by reading using folded and reindexing it via setmapped.

valuesetOf :: Hashable a => Getting (HashSet a) s a -> s -> HashSet a

Construct a set from a Getter, Fold, Control.Lens.Traversal.Traversal, Control.Lens.Lens.Lens or Control.Lens.Iso.Iso.

setOf :: Hashable a         => Getter s a     -> s -> HashSet a
setOf :: (Eq a, Hashable a) => Fold s a       -> s -> HashSet a
setOf :: Hashable a         => Iso' s a       -> s -> HashSet a
setOf :: Hashable a         => Lens' s a      -> s -> HashSet a
setOf :: (Eq a, Hashable a) => Traversal' s a -> s -> HashSet a

valuehashMap

:: (Profunctor p, Functor f)
=> p (HashMap a ()) (f (HashMap a ()))
-> p (HashSet a) (f (HashSet a))

An Iso between a HashSet and a HashMap with unit values. \mathcal{O}(1).